Host-guest chemistry on living cells enabling recyclable photobiocatalytic cascade

Combining chemical and whole-cell catalysts enables sustainable chemoenzymatic cascade reactions. However, their traditional combination faces challenges in catalyst recycling and maintaining cell viability. Here, we introduce a supramolecular host-guest strategy that efficiently attaches photocatalysts to bacterial cells, facilitating recyclable photobiocatalysis. This method involves attaching a cationic polyethylenimine (PEI) polymer, functionalized with β-cyclodextrin (β-CD), to E. coli cells. The polymer attachment is biocompatible and protective, safeguarding the cells from harsh conditions such as UV radiation and organic solvents, without causing cell death. Additionally, the presence of β-CD imparts a plug-and-play capability to the cells, enabling the straightforward integration of guest photocatalysts - specifically anthraquinone - onto the cell surface through host-guest interactions. This effective combination of cellular and chemical catalysts promotes efficient photobiocatalytic cascades and supports the photocatalyst's recycling and reuse. This supramolecular system thus represents a promising platform for advancing photobiocatalysis in cascade synthesis.